1. Field of the Invention
This invention relates to an electronic device with a key input section, such as an electronic dictionary, an electronic notebook, an electronic calculator, a mobile phone, or a PDA (personal digital assistance).
2. Description of the Related Art
For example, in such an electronic device as a mobile phone described in Japanese patent Application KOKAI publication No. 10-004273, in order to reduce the number of parts, a device housing for accommodating electronic parts is configured by an upper case and a lower case and a rubber-made annular packing with a key sheet is sandwiched between a peripheral region of the upper case and that of the lower case.
Specifically, in this electronic device, the rubber-made annular packing and the key sheet are formed integrally. The rubber-made annular packing is engaged with an annular groove formed in and extending along a whole peripheral region of the upper case, and then the upper and lower cases are joined so as to press the annular packing by a pressing rib formed on and extending along a whole peripheral region of the lower case.
In such a conventional configuration, a central region of the key sheet tends to sag and is hard to be in contact with the inner surface of the upper case closely.
Therefore, when the lower case on which electronic parts are mounted is joined to the upper case in the above described state, the sagging central region of the key sheet is pressed by the electronic parts on the lower case so that the central region is easily shifted from a predetermined position and the key sheet can not be arranged in the device housing correctly.